Motor and method for manufacturing motor

Abstract

The invention provides a motor and a manufacturing method of the motor. The motor is provided with a connecting part which is obtained by electrically connecting the common wires of the plurality of coil groups and connecting the common wires of the plurality of coil groups, and the connecting part extends from the inner part in the radial direction to the outer part in the radial direction or from the outer part in the radial direction to the inner part in the radial direction in a slot which is a part between teeth adjacent in the circumferential direction. The motor is provided with a sealing part which at least seals the connecting part.

Description

Technical Field

[0001] The present invention relates to a motor and a method for manufacturing the same. Background Art

[0002] An existing motor has a structure in which a lead-out hole for leading out a common wire included in a plurality of lead-out wires of a coil is provided in a base portion (see Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-135076 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In an environment where moisture is likely to adhere, the requirements for applying a motor are increasing. In an existing motor with the present structure, when moisture adheres to the common wire, corrosion may occur.

[0008] Therefore, an object of the present invention is to provide a motor capable of suppressing corrosion of a common wire caused by moisture adhesion.

[0009] Means for Solving the Problems

[0010] An exemplary motor of the present invention includes: a rotor that rotates about a central axis; and a stator that has a plurality of coil groups disposed on a plurality of teeth radially opposed to the rotor. Each of the coil groups includes: at least one coil formed of a continuous wire; and a common wire provided at an end of the wire and exposing a conductive portion. There is a connecting portion obtained by electrically connecting and joining the common wires of the plurality of coil groups. The connecting portion extends from the inside in the radial direction to the outside in the radial direction or from the outside in the radial direction to the inside in the radial direction in a slot, which is a portion between the circumferentially adjacent teeth. There is a sealing portion that seals at least the connecting portion.

[0011] Advantages of the Invention

[0012] According to the exemplary motor of the present invention, corrosion of the connecting portion that electrically connects the common wires to each other caused by moisture adhesion can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic cross-sectional view of a motor according to an embodiment.

[0014] Figure 2 is a schematic perspective view of a stator.

[0015] Figure 3 is a diagram showing a wiring state of a plurality of coil groups.

[0016] Figure 4 It is a schematic diagram showing the structure of a wire.

[0017] Figure 5 It is a schematic perspective view of a connecting part that gathers common lines together.

[0018] Figure 6 It is an enlarged cross-sectional view of a stator core with a connecting part fixed thereto, cut by a plane including the central axis.

[0019] Figure 7 It is a bottom view of a circuit board as viewed from below in the axial direction.

[0020] Figure 8 It is an enlarged cross-sectional view of a state where a U-phase lead wire is installed on a U-phase pad.

[0021] Figure 9 It is a flow chart of a manufacturing process of a motor.

[0022] Figure 10 It is a schematic diagram showing a state where a common line is inserted into a solder bath.

[0023] Figure 11 It is a schematic diagram showing a state where a lead wire is inserted into a solder bath.

[0024] Figure 12 It is a cross-sectional view of a motor of Modification 1.

[0025] Figure 13 It is a cross-sectional view of a motor of Modification 2.

[0026] Figure 14 It is a cross-sectional view of a motor of Modification 3.

[0027] Figure 15 It shows Figure 14 A schematic perspective view of the stator of the motor shown.

[0028] Symbol Explanation

[0029] 100, 100A, 100B, 100C - Motors, 10, 10C - Shafts, 20, 20C - Rotors, 21 - Rotor housing, 211 - Rotor hub, 212 - Rotor barrel, 213 - Rotor boss, 22 - Rotor magnets, 30, 30C - Stators, 31, 31C - Stator cores, 311, 311C - Back of the core, 312, 312C - Teeth, 313, 313C - Slots, 32U - U - phase coil group, 32V - V - phase coil group, 32W - W - phase coil group, 321U - U - phase common line, 321V - V - phase common line, 321W - W - phase common line, 322U - U - phase lead - out wire, 322V - V - phase lead - out wire, 322W - W - phase lead - out wire, 33U, 33V, 33W, 33C - Coils, 34 - Conductive wire, 341 - Conductive part, 342 - Insulating coating, 343 - Exposed part, 35, 35A, 35B, 35C - Connecting parts, 36, 36C - Sealing parts, 40 - Bottom plate, 41 - Holding part, 411 - Inner circumferential surface, 412 - Outer circumferential surface, 40C - Outer shell, 41C - Bottom plate, 42C - Outer shell body, 50, 50C - Circuit board, 51 - Mounting part, 52 - Pattern surface, 53 - Wiring pattern, 531U - U - phase pad, 531V - V - phase pad, 531W - W - phase pad, 54U, 54V, 54W - Through - holes, 55 - Cover member, 60, 60C - Bearings, Ax - Central axis, IU - U - phase current, IV - V - phase current, IW - W - phase current, Tp - Electronic component. Detailed implementation mode

[0030] Hereinafter, with reference to the drawings, a motor unit according to an embodiment of the present invention will be described. In addition, the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention.

[0031] In this specification, the direction parallel to the central axis Ax of the shaft 10 of the motor 100 is defined as the "axial direction". And, the direction orthogonal to the central axis Ax is defined as the "radial direction", and the circumferential direction centered on the central axis Ax is defined as the "circumferential direction". In addition, hereinafter, Figure 1 Based on the state shown, the upper side is referred to as the upper side in the axial direction, and the opposite side is referred to as the lower side in the axial direction for explanation.

[0032] In addition, in this specification, "annular" includes not only a shape that is seamlessly and continuously connected throughout the circumferential region centered on the central axis Ax, but also a shape that has one or more gaps in a part of the entire region centered on the central axis Ax. In addition, it also includes a shape that depicts a closed curve on a surface intersecting the central axis Ax centered on the central axis Ax.

[0033] Moreover, in this specification, the situation referred to as "parallel directions" includes not only the situation of being completely parallel, but also the situation of being approximately parallel. Furthermore, the situation of "extending along" a specified direction or plane includes not only the situation of extending strictly along the predetermined direction, but also the situation of extending along a direction inclined within a range of less than 45° relative to the strict direction. In addition, "perpendicular" and "orthogonal" respectively include not only the situation where the two intersect at 90 degrees, but also the situation where they are substantially perpendicular and the situation where they are substantially orthogonal. In other words, "parallel", "perpendicular" and "orthogonal" respectively include the situation where there is an angular offset in the positional relationship of the two that does not deviate from the main purpose of the present invention.

[0034] Note that these names are used only for explanation and do not limit actual positional relationships, directions, names, etc.

[0035] Motor 100

[0036] Hereinafter, a motor 100 according to an exemplary embodiment of the present invention will be described with reference to the drawings. Figure 1 It is a schematic cross-sectional view of a motor 100 according to one embodiment. Figure 1 The cross-sectional structure of the motor 100 is shown when it is virtually cut along a plane including the central axis.

[0037] like Figure 1 As shown, the motor 100 includes a shaft 10, a rotor 20, a stator 30, a base plate 40, a circuit board 50, and a bearing 60. The motor 100 is a so-called outer rotor type brushless DC motor.

[0038] <Axis 10>

[0039] The shaft 10 extends axially along the central axis Ax and has a cylindrical shape centered on the central axis Ax. At least a portion of the shaft 10 is disposed within a retaining portion 41 of the base plate 40, which will be described later, and is rotatably retained by the retaining portion 41 via a bearing 60. In other words, the shaft 10 is a rotating shaft that can rotate about the central axis Ax. Alternatively, in the motor 100, the shaft 10 can be a fixed shaft fixed to the base plate 40. In this case, the bearing 60 is disposed between the shaft 10 and the rotor 20, and the rotor 20 is supported so as to be rotatable relative to the shaft 10.

[0040] Rotor 20

[0041] like Figure 1 As shown, the rotor 20 includes a rotor housing 21 and a rotor magnet 22. The rotor housing 21 is a covered cylindrical shape formed of a magnetic material and includes a rotor hub 211 and a rotor cylinder portion 212.

[0042] The rotor hub 211 has a cylindrical rotor boss 213 that extends radially downward from the central portion in the axial direction. The rotor hub 211 is in the shape of a flat plate extending in the radial direction. The rotor boss 213 is a cylindrical shape extending along the central axis Ax, and its center line coincides with the central axis Ax. The upper end of the shaft 10 in the axial direction is fixed to the rotor boss 213. Thus, the shaft 10 and the rotor housing 21 are fixed.

[0043] The rotor boss 213 and the shaft 10 are fixed here by press-fitting, but are not limited thereto. As the fixing method of the rotor boss 213 to the shaft 10, methods such as adhesion, cladding, and screw fixing that can firmly fix the rotor boss 213 to the shaft 10 can be widely adopted. Thus, the rotor 20 is fixed to the shaft 10. Therefore, the rotor 20 rotates about the central axis Ax.

[0044] The rotor cylinder portion 212 is cylindrical and extends axially downward from the outer edge in the radial direction of the rotor hub 211. A plurality of rotor magnets 22 are fixed to the inner peripheral surface of the rotor cylinder portion 212. The plurality of rotor magnets 22 are cylindrical. The rotor magnets 22 surround the stator 30 (especially the stator core 31 described later) from the outside in the radial direction and are opposed to each other in the radial direction. The plurality of rotor magnets 22 are arranged in the circumferential direction. The magnetic poles (S pole, N pole) on the inner side in the radial direction of the rotor magnets 22 adjacent in the circumferential direction are alternately different. In addition, the rotor 20 has a structure with a plurality of rotor magnets 22, but a cylindrical magnet with magnetic poles alternately arranged as N poles and S poles in the circumferential direction on the inner peripheral surface can also be used.

[0045] As described above, the cylindrical rotor cylinder portion 212 is formed of a magnetic material, and when the rotor magnets 22 are installed on the inner peripheral surface, the rotor cylinder portion 212 functions as a rotor yoke.

[0046] <Stator 30>

[0047] Figure 2 is a schematic perspective view of the stator 30. As Figure 1 , Figure 2 shown, the stator 30 includes a stator core 31, an insulator (not shown), and a plurality of coil groups 32U, 32V, 32W. The stator core 31 is a laminate formed by laminating electromagnetic steel sheets in the axial direction. In addition, the stator core 31 is not limited to a laminate formed by laminating electromagnetic steel sheets. For example, it can also be a single component such as powder sintering or casting.

[0048] The stator core 31 has an annular core back 311 and a plurality of teeth 312. The inner peripheral surface 310 of the annular core back 311 is fixed to the holding portion 41 of the bottom plate 40. Thus, the center of the stator core 31 coincides with the central axis Ax of the motor 100. In addition, a fixing member may be interposed between the core back 311 and the holding portion 41.

[0049] A plurality of teeth 312 extend radially outward from the outer peripheral surface of the back portion 311 of the iron core. The plurality of teeth 312 are arranged at equal intervals in the circumferential direction. The outer peripheral surfaces of the plurality of teeth 312 are opposed to the inner peripheral surface of the rotor magnet 22 of the rotor 20 in the radial direction. The insulator is formed of an insulating material such as resin.

[0050] The stator 30 has a plurality of coil groups 32U, 32V, and 32W disposed on the plurality of teeth 312 opposed to the rotor 20 in the radial direction. In the motor 100, by supplying currents with different phases to the coil groups 32U, 32V, and 32W at appropriate timings, an attractive force or a repulsive force is generated between the rotor magnets, and the rotor 20 rotates. In addition, the plurality of coil groups are set as a U-phase coil group 32U, a V-phase coil group 32V, and a W-phase coil group 32W, and the currents supplied to the respective coil groups are set as a U-phase current IU, a V-phase current IV, and a W-phase current IW.

[0051] Figure 3 is a diagram showing the wiring state of the plurality of coil groups 32U, 32V, and 32W. As Figure 3 shown, the stator 30 has a structure with fifteen teeth 312, and the U-phase coil group 32U has five coils 33U. In the U-phase coil group 32U, the five coils 33U are connected in series. The V-phase coil group 32V has five coils 33V. In the V-phase coil group 32V, the five coils 33V are connected in series. The W-phase coil group 32W has five coils 33W. In the W-phase coil group 32W, the five coils 33W are connected in series. That is, each of the coil groups 32U, 32V, and 32W has at least one coil 33U, 33V, or 33W formed by a continuous wire 34.

[0052] Moreover, one of the wires 34 extending from both ends of the U-phase coil group 32U in which the coils 33U are connected in series is a U-phase common line 321U, and the other is a U-phase lead wire 322U. Similarly, one of the wires 34 at both ends of the V-phase coil group 32V is a V-phase common line 321V, and the other is a V-phase lead wire 322V. In addition, one of the wires 34 at both ends of the W-phase coil group 32W is a W-phase common line 321W, and the other is a W-phase lead wire 322W. That is, the coil groups 32U, 32V, and 32W have common lines 321U, 321V, and 321W provided at the ends of the wire 34 and exposing the conductive portion 341.

[0053] Each of the coils 33U, 33V, and 33W is formed by winding a wire around a tooth 312 covered with an insulator (not shown). Figure 4 is a schematic diagram showing the structure of the wire 34. As Figure 4As shown, the wire 34 has a conductive portion 341 and an insulating coating 342. The wire 34 has a structure in which the outer peripheral surface of the conductive portion 341 is covered with the insulating coating 342. In addition, as the wire 34, a so-called enameled wire in which the conductive portion 341 made of copper is covered with the insulating coating 342 made of enameled resin can be cited, but it is not limited thereto. The wire 34 can be widely adopted as a wire in which the outer peripheral portion of a conductive member with low resistance is covered with a member having insulating properties.

[0054] The coils 33U with each other, the coils 33V with each other, and the coils 33W with each other are all connected by the wire 34. The wire connecting the coils to each other, so-called jumper wire, is installed in a mounting portion (not shown) formed in the insulator. Thereby, it is possible to suppress the slack of the jumper wire and suppress the contact between the slack jumper wire and the shaft 10 and the rotor 20 to cause disconnection.

[0055] Moreover, in the motor 100, the U-phase common line 321U of the U-phase coil group 32U, the V-phase common line 321V of the V-phase coil group 32V, and the W-phase common line 321W of the W-phase coil group 32W are connected. That is, in the motor 100, the three coil groups 32U, 32V, and 32W are star-connected. The U-phase common line 321U, the V-phase common line 321V, and the W-phase common line 321W are gathered together and electrically connected through the connecting portion 35. The details of the connecting portion 35 will be described later.

[0056] In addition, the front ends of the U-phase lead wire 322U, the V-phase lead wire 322V, and the W-phase lead wire 322W have exposed portions 343 obtained by removing the insulating coating 342. That is, the coil groups 32U, 32V, and 32W have lead wires 322U, 322V, and 322W provided at the ends of the wire 34 to expose the conductive portion 341. And solder attachment portions 323U, 323V, and 323W are formed by attaching solder to the surfaces of the exposed portions 343. And the solder attachment portions 323U, 323V, and 323W are electrically connected to the pads 531U, 531V, and 531W provided on the circuit board 50 through the solder 56. The details of the connection of the U-phase lead wire 322U, the V-phase lead wire 322V, and the W-phase lead wire 322W to the circuit board 50 will be described later.

[0057] <Base plate 40>

[0058] The base plate 40 is a flat plate shape that extends in a direction orthogonal to the central axis Ax. The base plate 40 is disposed axially below the rotor 20 and the stator 30. And the base plate 40 has a cylindrical holding portion 41 that extends upward in the axial direction at the central portion in the radial direction. The holding portion 41 and the base plate 40 are integrally formed. In addition, it can also be configured that the holding portion 41 is formed separately from the base plate 40 and the holding portion 41 is fixed to the base plate 40.

[0059] On the inner peripheral surface 411 of the holding part 41, two bearings 60 are arranged in the axial direction. The two bearings 60 rotatably support the shaft 10 relative to the holding part 41. The stator core 31 is fixed to the holding part 41 in a state where the inner peripheral surface of the core back 311 of the stator core 31 is in contact with the outer peripheral surface 412 of the holding part 41. The fixing method of the holding part 41 to the core back 311 is press-fitting here. However, the fixing method of the holding part 41 to the core back 311 is not limited to press-fitting, and fixing methods such as adhesion, welding, cladding, and screw fixing that can firmly fix the holding part 41 and the core back 311 can be widely adopted.

[0060] <Connection part 35>

[0061] Figure 5 FIG. is a schematic perspective view of the connection part 35 that gathers the common lines 321U, 321V, and 321W together. As Figure 5 shown, the front ends of the U-phase common line 321U, the V-phase common line 321V, and the W-phase common line 321W are stripped of the insulation coating 342 and are twisted. Then, by brazing the conductive parts 341 at the front ends of the common lines 321U, 321V, and 321W that are integrated by twisting, the connection part 35 is formed. That is, the connection part 35 electrically connects the multiple common lines 321U, 321V, and 321W to each other and has a structure in which the multiple common lines 321U, 321V, and 321W are brazed. Since the common lines 321U, 321V, and 321W are joined by brazing to form the connection part 35, the common lines 321U, 321V, and 321W can be electrically connected to each other in the connection part 35.

[0062] The U-phase common line 321U, the V-phase common line 321V, and the W-phase common line 321W are electrically connected via the connection part 35. That is, the stator 30 has a connection part 35 that electrically connects and joins the common lines 321U, 321V, and 321W of the multiple coil groups 32U, 32V, and 32W.

[0063] Here, the fixing of the connection part 35 to the stator core 31 will be described. Figure 6 FIG. is an enlarged cross-sectional view of the stator core 31 to which the connection part 35 is fixed, cut by a plane including the central axis Ax.

[0064] As Figure 2 、 Figure 6As shown, the connecting portion 35 is disposed inside the slot 313 formed between the circumferentially adjacent teeth 312. Further, in the motor 100 of the present embodiment, since it is an outer rotor motor, the teeth 312 of the stator core 31 extend from the core back 311 disposed radially inward toward the radially outward. Therefore, the common lines 321U, 321V, and 321W are continuous with the respective coils radially inward in the stator core 31. And the connecting portion 35 extends from the inside in the radial direction to the outside in the radial direction within the slot 313. That is, the connecting portion 35 is located radially outward as it approaches the front end. In addition, the connecting portion 35 may be disposed at a twisted position with respect to the central axis Ax.

[0065] That is, the connecting portion 35 extends from the inside in the radial direction to the outside in the radial direction within the slot 313, which is the portion between the circumferentially adjacent teeth 312. In addition, the connecting portion 35 may be configured to extend in a direction intersecting the central axis Ax. Moreover, the connecting portion 35 may be in the radial direction centered on the central axis Ax.

[0066] In the stator 30, the U-phase common line 321U, the V-phase common line 321V, and the W-phase common line 321W are disposed in the upper part in the axial direction. Therefore, as Figure 5 shown, the connecting portion 35 that twists and gathers the common lines is disposed in the upper part in the axial direction within the slot 313.

[0067] As described above, the wire 34 constituting the connecting portion 35 has the insulating coating 342 disposed on the outer periphery removed and is brazed. When the portion brazed to the connecting portion 35 is exposed, corrosion, so-called rusting, may occur due to the influence of external moisture. Especially in the case of the motor 100 used in a high-temperature and high-humidity environment, rusting of the connecting portion 35 is likely to occur. Therefore, the motor 100 has a sealing portion 36 that seals the connecting portion 35. That is, the stator 30 of the motor 100 has at least the sealing portion 36 that seals the connecting portion 35.

[0068] Here, the sealing portion 36 will be described. The sealing portion 36 is a member that covers the connecting portion 35. Examples of the sealing portion 36 include resins formed of materials that can inhibit the passage of moisture. Thereby, moisture from the outside is inhibited from reaching the connecting portion 35. In addition, as the sealing portion 36, an ultraviolet curable resin having the property of inhibiting the passage of moisture and cured by ultraviolet irradiation, a thermosetting resin cured by heating, a resin cured by a chemical reaction, etc. can be cited. Since the sealing portion 36 is formed of resin, the connecting portion 35 can be easily sealed. Therefore, the number of components can be suppressed to be small, and the man-hours of the manufacturing process can be reduced.

[0069] The sealing part 36 is disposed between the two ends of the coils 33U and 33W in the direction along the central axis Ax. With such a configuration, the sealing part 36 does not protrude outward beyond the two ends of the stator 30 in the two directions along the central axis Ax. Thereby, contact between the rotor 20 and the sealing part 36 can be suppressed. Further, the connecting part 35 is arranged to be offset toward one side in the direction along the central axis Ax from the central part in the direction along the central axis Ax. Therefore, the sealing part 36 is disposed on one side in the direction along the central axis Ax of the central part in the slot 313 in the direction along the central axis Ax. With such a configuration, when the sealing part 36 is formed after the connecting part 35 is disposed inside the slot 313, since it is formed in a part close to the axial opening of the slot 313, resin can easily fill around the connecting part 35. As a result, the sealing part 36 can be easily formed.

[0070] Further, the sealing part 36 covers the connecting part 35 and is fixed to the coils 33U and 33W wound around the teeth 312 adjacent to the slot 313. Additionally, the sealing part 36 may also be fixed to the teeth 312. That is, the sealing part 36 is fixed to the teeth 312 or the coils 33U and 33W disposed on the teeth 312 that are circumferentially adjacent to the slot 313 in which the sealing part 36 is disposed. Thereby, the connecting part 35 is fixed, so movement of the connecting part 35 is suppressed when the motor 100 operates, and contact between the connecting part 35 and the rotor 20 is suppressed. Further, in the motor 100, the connecting part 35 may also be disposed at the axially lower end of the slot 313.

[0071] By configuring the connecting part 35 and the sealing part 36 as described above, moisture attachment to the connecting part 35 can be suppressed by the sealing part 36. Thereby, corrosion of the connecting part 35 caused by moisture attachment can be suppressed. By adopting such a structure, a motor 100 that can be used even in places where moisture easily attaches to the connecting part 35 or where condensation easily occurs can be provided.

[0072] <Circuit board 50>

[0073] Figure 7 is a bottom view of the circuit board 50 as viewed from axially below. As Figure 1 shown, the circuit board 50 is disposed between the stator core 31 of the holding part 41 and the bottom plate 40. As Figure 7 shown, the circuit board 50 is in the shape of a semicircular plate. The outer periphery of the circuit board 50 has a linear part and an arc-shaped part. And, a concave mounting part 51 is formed at the central part of the linear part of the circuit board 50. The circuit board 50 is fixed to the holding part 41 by the mounting part 51 contacting the outer peripheral surface 412 of the holding part 41. Additionally, the circuit board 50 of the present embodiment may also be in the shape of a circular ring.

[0074] The axially lower surface of the circuit board 50 is a pattern surface 52, and a wiring pattern 53 composed of a conductive film having conductivity is formed on the pattern surface 52. Further, a plurality of electronic components Tp are mounted on the wiring pattern 53 to form a circuit. That is, the circuit board 50 has the wiring pattern 53 formed on at least one surface in the thickness direction and constituting the circuit. The electronic components Tp are arranged on the pattern surface 52, and surface mounting is performed in which the terminals are electrically connected to the pattern wiring. In addition, regarding the mounting of the electronic components Tp, it is not limited to surface mounting, and through-hole mounting may also be used.

[0075] The motor drive circuit includes a control circuit, a drive circuit, an inverter circuit, etc. Based on signals from the outside for supporting the rotational speed and torque of the motor 100, appropriate current values and timings (phases) of the U-phase current IU, V-phase current IV, and W-phase current IW are supplied to the U-phase coil group 32U, V-phase coil group 32V, and W-phase coil group 32W, respectively. That is, the circuit board 50 is connected to each coil group 32U, 32V, 32W and drives each coil group 32U, 32V, 32W.

[0076] As Figure 7 shown, the circuit board 50 has through-holes 54U, 54V, 54W penetrating in the thickness direction. The U-phase lead wire 322U penetrates through the through-hole 54U. The V-phase lead wire 322V penetrates through the through-hole 54V. The W-phase lead wire 322W penetrates through the through-hole 54W. That is, the lead wires 322U, 322V, 322W penetrate through the through-holes 54U, 54V, 54W.

[0077] The wiring pattern 53 has a U-phase pad 531U, a V-phase pad 531V, and a W-phase pad 531W. The U-phase pad 531U is arranged at a position away from the through-hole 54U, the V-phase pad 531V is arranged at a position away from the through-hole 54V, and the W-phase pad 531W is arranged at a position away from the through-hole 54W. That is, the through-holes 54U, 54V, 54W are arranged avoiding the wiring pattern 53.

[0078] The lead wires 322U, 322V, 322W are led out to positions away from the through-holes 54U, 54V, 54W, and the exposed portions 343 of the lead wires 322U, 322V, 322W are brought into contact with and fixed to the pads 531U, 531V, 531W. Thus, as long as at least a part of the exposed portions 343 of the lead wires 322U, 322V, 322W is in contact with the pads 531U, 531V, 531W, the exposed portions 343 can be shortened.

[0079] Further, the exposed portion 343 of the U-phase lead wire 322U is electrically connected to the U-phase pad 531U, the exposed portion 343 of the V-phase lead wire 322V is electrically connected to the V-phase pad 531V, and the exposed portion 343 of the W-phase lead wire 322W is electrically connected to the W-phase pad 531W. That is, the exposed portions 343 of the lead wires 322U, 322V, and 322W are electrically connected to the wiring pattern 53. The motor drive circuit is connected to the U-phase pad 531U, the V-phase pad 531V, and the W-phase pad 531W.

[0080] Next, the connection states of the U-phase lead wire 322U, the V-phase lead wire 322V, and the W-phase lead wire 322W with the U-phase pad 531U, the V-phase pad 531V, and the W-phase pad 531W will be described with reference to the drawings. The U-phase lead wire 322U, the V-phase lead wire 322V, and the W-phase lead wire 322W all have the same structure. In addition, the U-phase pad 531U, the V-phase pad 531V, and the W-phase pad 531W all have the same structure. Therefore, for the sake of representation, the U-phase lead wire 322U and the U-phase pad 531U will be described as representatives. Figure 8 FIG. is an enlarged cross-sectional view of the state where the U-phase lead wire 322U is mounted on the U-phase pad 531U.

[0081] As Figure 8 shown, the stator core 31 is disposed above the circuit board 50 in the axial direction. Therefore, the U-phase lead wire 322U is wired from the upper direction to the lower direction of the circuit board 50 in the axial direction. And the U-phase lead wire 322U penetrates the through hole 54U formed in the circuit board 50 from the upper direction to the lower direction in the axial direction.

[0082] An exposed portion 343 obtained by removing the insulating coating 342 is formed at the front end of the U-phase lead wire 322U. Thus, the exposed portion 343 at the front end of the U-phase lead wire 322U is disposed outside the through hole 54U. And the outer surface of the exposed portion 343 at the front end of the U-phase lead wire 322U is covered with solder to form a solder attachment portion 323U. And the solder attachment portion 323U is brought into contact with the U-phase pad 531U and electrically connected through the solder. The V-phase lead wire 322V and the W-phase lead wire 322W are also electrically connected to the V-phase pad 531V and the W-phase pad 531W in the same manner. By configuring in this way, the U-phase current IU is supplied to the U-phase coil group 32U via the U-phase pad 531U and the U-phase lead wire 322U. Similarly, the V-phase current IV is supplied to the V-phase coil group 32V, and the W-phase current IW is supplied to the W-phase coil group 32W.

[0083] Further, the circuit board 50 has a cover member 55. The cover member 55 covers at least the wiring pattern 53 of the circuit board 50. In addition, in the circuit board 50 of the present embodiment, the cover member 55 is configured to cover the entire surface of the pattern surface 52. The cover member 55 seals the exposed portions 343 of the lead wires 322U, 322V, and 322W.

[0084] The cover member 55 is made of resin, for example. Thereby, the cover member 55 can be formed into a shape that matches the wiring pattern 53 formed on the circuit board 50.

[0085] Thereby, it is possible to suppress foreign matters such as water, dust, and dirt from adhering to the wiring pattern 53 and the U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W mounted on the wiring pattern 53. By adopting such a structure, it is possible to provide the motor 100 that can be used even in places where moisture easily adheres to the connection part or where dew condensation easily occurs.

[0086] In addition, the cover member 55 is not limited to resin, and a structure having insulation properties and capable of reliably covering the wiring pattern 53 can be widely adopted. In the motor 100 of the present embodiment, the cover member 55 may be made of a resin having fluidity, and may be formed by flowing the resin on the pattern surface 52 of the circuit board 50 and then curing it.

[0087] In addition, a portion of the wire 34 constituting the U-phase lead wire 322U covered with the insulation coating 342 is disposed inside the through hole 54U. Similarly, a portion of the wire 34 constituting the V-phase lead wire 322V covered with the insulation coating 342 is disposed inside the through hole 54V. A portion of the wire 34 constituting the W-phase lead wire 322W covered with the insulation coating 342 is disposed inside the through hole 54W. That is, the portions of the wires 34 of the lead wires 322U, 322V, and 322W covered with the insulation coating 342 are disposed inside the through holes 54U, 54V, and 54W.

[0088] By configuring in this way, the exposed portions 343 of the wire 34 are not disposed inside the through holes 54U, 54V, and 54W. Therefore, even when moisture flows into the through holes 54U, 54V, and 54W, it is possible to suppress the adhesion of moisture to the U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W, and suppress corrosion. Moreover, even when the inner diameters of the through holes 54U, 54V, and 54W are small and the resin constituting the cover member 55 cannot flow in, it is possible to suppress the corrosion of the U-phase lead wire 322U, V-phase lead wire 322V, and W-phase lead wire 322W.

[0089] As Figure 8As shown, the shortest distance between the U-phase pad 531U and the via hole 54U is longer than the length of the exposed portion 343 formed at the front end of the U-phase lead wire 322U. In addition, the shortest distance between the V-phase pad 531V and the via hole 54V is longer than the length of the exposed portion 343 formed at the front end of the V-phase lead wire 322V. The shortest distance between the W-phase pad 531W and the via hole 54W is longer than the length of the exposed portion 343 formed at the front end of the W-phase lead wire 322W. That is, the shortest distances between the pads 531U, 531V, 531W connecting the exposed portions 343 of the lead wires 322U, 322V, 322W and the via holes 54U, 54V, 54W penetrated by the lead wires 322U, 322V, 322W are longer than the lengths of the exposed portions 343 of the lead wires 322U, 322V, 322W.

[0090] With such a configuration, it is possible to prevent the exposed portions 343 of the wires 34 constituting the U-phase lead wire 322U, the V-phase lead wire 322V, and the W-phase lead wire 322W from being disposed in the via holes 54U, 54V, 54W. In addition, the exposed portion 343 is disposed at a position axially coincident with the pattern surface 52 of the circuit board 50. As a result, when the cover member 55 is disposed, the exposed portion 343 can be reliably sealed, and corrosion caused by moisture adhering to the exposed portion 343 can be suppressed.

[0091] In addition, in the motor 100 of the present embodiment, the circuit board 50 is disposed between the stator 30 and the bottom plate 40, but it is not limited thereto. For example, the circuit board 50 may be disposed on the side opposite to the bottom plate 40 with the stator 30 interposed therebetween in the axial direction.

[0092] <Manufacturing Method of Motor 100>

[0093] The manufacturing method of the motor 100 will be described with reference to the accompanying drawings. Figure 9 It is a flowchart showing the manufacturing process of the motor 100. As Figure 9As shown, in the manufacturing process of the motor 100, first, a coil group forming process (step S101) is performed. In this coil group forming process, coil groups 32U, 32V, and 32W are formed by winding a wire 34 around a plurality of teeth 312 extending in the radial direction of the stator core 31. After step S101, in the manufacturing process of the motor 100, a connection part forming process (step S102) is executed. In this connection part forming process, the insulating coatings 342 at the ends of the wires 34 of the coil groups 32U, 32V, and 32W are removed to form common wires 321U, 321V, and 321W that expose the conductive parts 341. The conductive parts 341 of the common wires 321U, 321V, and 321W are brought into contact with each other, and a connection part 35 is formed by solder. Additionally, in the case of soldering the parts where the common wires 321U, 321V, and 321W are in contact with each other, it can also be performed by inserting the concentrated common wires 321U, 321V, and 321W into a solder bath Pp1 filled with molten solder Wp (refer to Figure 10 ).

[0094] After step S102, in the manufacturing process of the motor 100, a connection part arranging process (step S103) is executed. In this connection part arranging process, the connection part 35 is arranged in a state of extending from the inner side in the radial direction to the outer side in the radial direction, or from the outer side in the radial direction to the inner side in the radial direction, in a portion between the circumferentially adjacent teeth 312, that is, in the slot 313. At this time, the connection part 35 is arranged to extend from the inner side in the radial direction to the outer side in the radial direction. After step S103, in the manufacturing process of the motor 100, a sealing part forming process (step S104) is executed. In this sealing part forming process, a resin with fluidity is made to flow into the portion of the slot 313 where the connection part 35 is arranged, and the resin is cured to form a sealing part 36.

[0095] In addition, after step S104, in the manufacturing process of the motor 100, a lead wire forming process (step S105) is executed. In this lead wire forming process, the insulating coatings 342 at the ends of the wires 34 of the coil groups 32U, 32V, and 32W are removed to form lead wires 322U, 322V, and 322W having exposed parts 121 that expose the conductive parts 341.

[0096] After step S105, in the manufacturing process of the motor 100, a solder attachment part forming process (step S106) is executed. In this solder attachment part forming process, a part of the front end of the above-mentioned exposed part 343 of the lead wires 322U, 322V, and 322W is immersed in a solder bath Pp2 filled with molten solder Wp to form solder attachment parts 323U, 323V, and 323W (refer to Figure 11 ). Additionally, the length of the solder attachment parts 323U, 323V, and 323W can be, for example, 5 mm or less.

[0097] After step S106, in the manufacturing process of the motor 100, a circuit connection process (step S107) is performed. In this circuit connection process, the solder attachment portions 323U, 323V, and 323W are inserted into the through holes 54U, 54V, and 54W formed in the circuit board 50, and the exposed portions 343 are brazed to the pads 531U, 531V, and 531W formed in the circuit board 50.

[0098] After step S107, in the manufacturing process of the motor 100, a cover member forming process (step S108) is performed. In this cover member forming process, a cover member 55 that covers the pattern surface 52 of the circuit board 50 is formed. In addition, the cover member 55 only needs to be a structure that covers at least the wiring pattern 53.

[0099] In addition, in the present embodiment, steps S105 to S108 are performed after steps S102 to S104, but the reverse may also be possible. In addition, they may be performed simultaneously.

[0100] In the manufacturing method of the motor 100 manufactured through the above-described processes, the coil groups 32U, 32V, and 32W of the stator 30 are formed, the connecting portion 35 is formed, and then brazing and the formation of the sealing portion 36 are performed. Therefore, even if deviations occur due to the shape and size of the motor 100, the connecting portion 35 can be reliably sealed. Thereby, corrosion caused by the attachment of moisture to the connecting portion 35 can be suppressed.

[0101] In addition, the coil groups 32U, 32V, and 32W of the stator 30 are formed, the lead wires 322U, 322V, and 322W are formed, and then solder attachment, through hole installation, and the formation of the cover member 55 are performed. Therefore, even if deviations occur due to the shape and size of the motor 100, the exposed portions 343 of the lead wires 322U, 322V, and 322W can be reliably sealed. Thereby, corrosion caused by the attachment of moisture to the lead wires 322U, 322V, and 322W can be suppressed.

[0102] In addition, the U-phase pad 531U, V-phase pad 531V, and W-phase pad 531W are arranged away from the through holes 54U, 54V, and 54W. Therefore, it is only necessary to penetrate the through holes 54U, 54V, and 54W. Thus, the solder attachment portions 323U, 323V, and 323W can be shorter. As the lengths of the solder attachment portions 323U, 323V, and 323W, for example, 5 mm can be cited. By making the lengths of the solder attachment portions 323U, 323V, and 323W shorter, when the exposed portions 343 at the front ends of the lead wires 322U, 322V, and 322W are immersed in the solder bath Pp2 in which the molten solder Wp is accumulated, contact between the stator 30 and the solder bath Pp2 can be suppressed. Thereby, the solder attachment portions 323U, 323V, and 323W can be manufactured safely.

[0103] <Variation Example 1>

[0104] As Figure 12 shown in the motor 100A of, the connecting portion 35A may also be structured such that it is arranged radially outward and axially below the radially inner side. Figure 12 is a cross-sectional view of the motor 100A of Variation Example 1. In addition, when the connecting portion 35A is arranged at the axially lower end portion of the slot 313, it may also be structured such that it is arranged radially outward and radially above the radially inner side.

[0105] <Variation Example 2>

[0106] In addition, as Figure 13 shown in the motor 100B of, the connecting portion 35B may also be structured such that it has a portion bent axially downward on the radially outer side and a part of the front end portion extends radially inward. Figure 13 is a cross-sectional view of the motor 100B of Variation Example 2. In addition, when the connecting portion 35B is arranged at the axially lower end portion of the slot 313, it may also be structured such that the connecting portion 35B bends upward and a part of the front end portion extends radially inward.

[0107] By configuring the motor 100A and the motor 100B in this way, even if the lengths of the connecting portions 35A and 35B are longer than the radial length of the slot 313, they can be accommodated inside the slot 313. Thereby, the entire connecting portions 35A and 35B can be sealed by the sealing portion 36, and corrosion of the connecting portions 35A and 35B due to moisture can be suppressed.

[0108] <Variation Example 3>

[0109] Figure 14 is a cross-sectional view of the motor 100C of Variation Example 3. Figure 15 is showing Figure 14 the schematic perspective view of the stator 30C of the motor 100C shown in. As Figure 14As shown, the motor 100C has a shaft 10C, a rotor 20C, a stator 30C, a housing 40C, a circuit board 50C, and a bearing 60C.

[0110] The motor 100C has a housing 40C, and the housing 40C has a bottom plate 41C and a housing body 42C. The housing body 42C is a covered cylindrical shape, and in the motor 100C, the housing body 42C is a cylindrical shape extending in the axial direction. Also, the upper end in the axial direction of the housing body 42C has a cover portion that expands toward the radially inner side. And, the bottom plate 41C is attached to the lower end in the axial direction of the housing body 42C. The housing body 42C is fixed to the bottom plate 41C.

[0111] The motor 100C is an inner-rotor type DC brushless motor, and the stator 30C is fixed to the inner peripheral surface of the housing body 42C. And, the shaft 10C fixed to the rotor 20C is rotatably supported by the cover portion of the housing body 42C and the bottom plate 41C via the bearing 60C with the central axis Ax as the center.

[0112] As Figure 15 shown, the stator 30C has a stator core 31C and a plurality of coil groups 32C. In addition, the plurality of coil groups 32C have the same structure as the above-mentioned U-phase coil group 32U, V-phase coil group 32V, and W-phase coil group 32W. And, each coil group 32C has the same number of coils 33C.

[0113] As Figure 15 shown, the stator core 31C has a core back 311C and a plurality of teeth 312C. The core back 311C is a cylindrical shape. And, the plurality of teeth 312C extend from the core back 311C toward the radially inner side. That is, the connecting portion 35C extends from the outer side in the radial direction to the inner side in the radial direction within the slot 313C, which is the portion between the circumferentially adjacent teeth 312C.

[0114] And, the common line of each coil group 32C is arranged in an insulator (not shown) arranged in the core back 311C, and the connecting portion 35C formed by collecting and brazing the common lines together is arranged in the slot 313C formed between the circumferentially adjacent teeth 312C. And, the connecting portion 35C extends from the outer side in the radial direction to the inner side in the radial direction in the slot 313C. And, the connecting portion 35C is sealed by a sealing portion 36C made of resin or the like, and is fixed to the coil 33C arranged in the tooth 312C adjacent to the slot 313C in the circumferential direction through the sealing portion 36C.

[0115] The connecting portion 35C is disposed at the upper or lower end in the axial direction of the slot 313C. With this configuration, when resin flows in to form the sealing portion 36C, the resin can reliably cover the periphery of the connecting portion 35C. Thereby, the connecting portion 35C can be reliably sealed, adhesion of moisture to the connecting portion 35C can be suppressed, and corrosion caused by the adhesion of moisture can be suppressed.

[0116] In the example shown above, the motors 100, 100A, 100B, and 100C are brushless DC motors, but are not limited thereto. As long as the motor has a structure in which coils are disposed in the stator, there is no particular limitation.

[0117] <Summary>

[0118] The present invention has the following structure.

[0119] (1) A motor having:

[0120] a rotor that rotates about a central axis; and

[0121] a stator having a plurality of coil groups disposed on a plurality of teeth that are radially opposed to the rotor,

[0122] each of the above coil groups having:

[0123] at least one coil formed of a continuous wire; and

[0124] a common wire provided at an end of the wire and exposing a conductive portion,

[0125] having a connecting portion obtained by electrically connecting and joining the common wires of the plurality of above coil groups,

[0126] the above connecting portion extending from the inner side in the radial direction to the outer side in the radial direction or from the outer side in the radial direction to the inner side in the radial direction in a slot which is a portion between the above teeth adjacent in the circumferential direction,

[0127] having a sealing portion that at least seals the above connecting portion.

[0128] (2) The motor according to (1), wherein

[0129] the above connecting portion extends in a direction intersecting the above central axis.

[0130] (3) The motor according to (2), wherein

[0131] the above connecting portion extends in the radial direction centered on the above central axis.

[0132] (4) The motor according to any one of (1) to (3), wherein

[0133] The above connecting part is a structure that electrically connects multiple above-mentioned common lines to each other and brazes multiple above-mentioned common lines to each other.

[0134] (5) The motor according to any one of (1) to (4), wherein

[0135] The above sealing part is fixed to the above tooth adjacent to the slot in which the above sealing part is arranged in the circumferential direction or to the above coil in which the above tooth is arranged.

[0136] (6) The motor according to any one of (1) to (5), wherein

[0137] The above sealing part is formed of resin.

[0138] (7) The motor according to any one of (1) to (6), wherein

[0139] The above sealing part is arranged between both ends of the above coil in the direction along the above central axis.

[0140] (8) The motor according to any one of (1) to (7), wherein

[0141] The above sealing part is arranged on one side of the above slot closer to the central part in the direction along the above central axis.

[0142] (9) A method for manufacturing a motor, comprising:

[0143] A coil group forming step of winding a wire around a plurality of teeth extending in the radial direction of the stator to form a plurality of coil groups;

[0144] A connecting part forming step of removing the insulating coating at the end of the wire of a plurality of above-mentioned coil groups to expose the conductive part to form a common line, bringing the conductive parts of the above-mentioned common lines into contact with each other, and forming a connecting part by brazing;

[0145] A connecting part arranging step of arranging the above connecting part in a state of extending from the inside in the radial direction to the outside in the radial direction or from the outside in the radial direction to the inside in the radial direction in a part between the above teeth adjacent in the circumferential direction, i.e., in the slot; and

[0146] A sealing part forming step of flowing a resin having fluidity into the part of the above slot where the above connecting part is arranged and curing the above resin to form a sealing part.

Claims

1. A motor, characterized in that, comprising: a rotor that rotates about a central axis; and a stator having a plurality of coil groups each including a plurality of teeth arranged to face the rotor in the radial direction, each of the coil groups comprising: at least one coil formed of a continuous wire; and a common wire provided at an end of the wire and exposing a conductive portion, having a connecting portion obtained by electrically connecting and joining the common wires of the plurality of coil groups, the connecting portion extending from the inside in the radial direction to the outside in the radial direction or from the outside in the radial direction to the inside in the radial direction in a slot that is a portion between the circumferentially adjacent teeth, having a sealing portion that at least seals the connecting portion.

2. The motor according to claim 1, wherein the connecting portion extends in a direction intersecting the central axis.

3. The motor according to claim 2, wherein the connecting portion extends in the radial direction about the central axis.

4. The motor according to claim 1, wherein the connecting portion electrically connects the plurality of common wires to each other and brazes the plurality of common wires to each other.

5. The motor according to claim 1, wherein the sealing portion is fixed to a tooth circumferentially adjacent to the slot in which the sealing portion is arranged or to a coil in which the tooth is arranged.

6. The motor according to claim 5, wherein the sealing portion is formed of resin.

7. The motor according to claim 1, wherein the sealing portion is arranged between both ends of the coil in the direction along the central axis.

8. The motor according to claim 1, wherein the sealing portion is arranged on one side in the direction along the central axis with respect to a central portion in the direction along the central axis of the slot.

9. A manufacturing method of a motor, characterized in that, comprising: a coil group forming step of winding a wire around a plurality of teeth extending in the radial direction of the stator to form a plurality of coil groups; a connecting portion forming step of removing an insulating coating at an end of the wire of the plurality of coil groups to form a common wire exposing a conductive portion, bringing the conductive portions of the common wires into contact with each other, and forming a connecting portion by brazing; a connecting portion arranging step of arranging the connecting portion in a slot that is a portion between the circumferentially adjacent teeth in a state of extending from the inside in the radial direction to the outside in the radial direction or from the outside in the radial direction to the inside in the radial direction; and a sealing portion forming step of causing a resin having fluidity to flow into a portion of the slot in which the connecting portion is arranged and curing the resin to form a sealing portion.

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